An orthogonal frequency division multiplexing (OFDM) communication system transmits high-speed data through a radio channel and uses a plurality of carriers that are orthogonal to each other. When an OFDM symbol is transmitted through a multi-path channel, the currently transmitted symbol may be affected by a previously transmitted symbol. In order to mitigate the inter-symbol interference (ISI) between OFDM symbols, a guard interval (GI) longer than the maximum delay spread of a channel is inserted between successive symbols. An OFDM symbol period is thus comprised of a sum of an effective symbol interval in which actual data is transmitted and a GI. A receiver detects and demodulates data associated with the effective symbol interval after removing the GI.
The concept of OFDM communication has been adopted in wireless standards such as the Digital Video Broadcasting-Terrestrial (DVB-T) standard, the Digital Audio Broadcasting (DAB) standard, the Institute of Electrical & Electronic Engineers (IEEE) 802.11a Local Area Network (LAN) standard, and the IEEE 802.16a Metropolitan Area Network standard. Accordingly, the OFDM scheme is currently being considered as a representative scheme for future use in 4th generation (4G) mobile communication systems.